1. Field of the Invention
The present invention relates to the field of accessing a biological lumen and closing the access port thereby created.
2. Description of the Related Art
A number of diagnostic and interventional vascular procedures are now performed translumenally, where a catheter is introduced to the vascular system at a convenient access location—such as the femoral, brachial, or subclavian arteries—and guided through the vascular system to a target location to perform therapy or diagnosis. When vascular access is no longer required, the catheter and other vascular access devices must be removed from the vascular entrance and bleeding at the puncture site must be stopped.
One common approach for providing hemostasis is to apply external force near and upstream from the puncture site, typically by manual compression. This method is time-consuming, frequently requiring one-half hour or more of compression before hemostasis. This procedure is uncomfortable for the patient and frequently requires  administering analgesics. Excessive pressure can also present the risk of total occlusion of the blood vessel, resulting in ischemia and/or thrombosis.
After hemostasis is achieved by manual compression, the patient is required to remain recumbent for six to eighteen hours under observation to assure continued hemostasis. During this time bleeding from the vascular access wound can restart, potentially resulting in major complications. These complications may require blood transfusion and/or surgical intervention.
Bioabsorbable fasteners have also been used to stop bleeding. Generally, these approaches rely on the placement of a thrombogenic and bioabsorbable material, such as collagen, at the superficial arterial wall over the puncture site. This method generally presents difficulty locating the interface of the overlying tissue and the adventitial surface of the blood vessel. Implanting the fastener too far from the desired location can result in failure to provide hemostasis. If, however, the fastener intrudes into the vascular lumen, thrombus can form on the fastener. Thrombus can embolize downstream and/or block normal blood flow at the thrombus site. Implanted fasteners can also cause infection and auto-immune reactions/rejections of the implant.
Suturing methods are also used to provide hemostasis after vascular access. The suture-applying device is introduced through the tissue tract with a distal end of the device located at the vascular puncture. Needles in the device draw suture through the blood vessel wall on opposite sides of the punctures, and the suture is secured directly over the adventitial surface of the blood vessel wall to close the vascular access wound.
To be successful, suturing methods need to be performed with a precise control. The needles need to be properly directed through the blood vessel wall so that the suture  is well anchored in tissue to provide for tight closure. Suturing methods also require additional steps for the surgeon.
Due to the deficiencies of the above methods and devices, a need exists for a more reliable vascular closure method and device. There also exists a need for a vascular closure device and method that does not implant a foreign substance and is self-sealing. There also exists a need for a vascular closure device and method requiring no or few extra steps to close the vascular site.